Yes here is your MOBO and it does have a PCIe x 16 slot and the GPU you are looking at may or may not work. The reason it the AMD cards are a 2.1 and the nVidia are a 2.0 and your MOBO is a 1.0.
Now they are all suppose to work with each other. The 2.1 cards have been known not to work with the 1.0 PCIe slots. So if you can test the card out before you buy to make sure it will work would be the way to go.
If It works then no problem. If it doesn't then look at a nVidia card like a GTS 450. the 2.0 ones will for sure work. The 2.1, 2.0, 1.0 is the speed at which the info travels Anyway here is your MOBO. Good luck to you.http://www.newegg.com/product/product.aspx?Item=N82E16813131545